RCM hybrid diffs - RC-Monster Forums

Nautilus · 12:08 PM

So after 1 year of the RCM V3 hybrid diffs sitting around, I finally decided to complete my brushless conversion for my nitro Revo. I am using a Kershaw E-Revo chassis with a new E-Revo tranny. The setup will use center dogbones and plastic outdrive shafts. Using a CC monster system and have 3s lipos waiting.

Question though, do I need to shim the RCM V3 hybrid diffs? If so, how?

suicideneil · 08.10.2009, 09:43 PM

They shouldnt need much shimming, at most one or two 10x8x0.5mm shims behind the head of the pinion gear, in between it & the inner bearing, just to set the pinion depth and mesh it correctly to the ring gear. Shouldnt have excessive play, or be tight feeling when rotaed by hand (got to allow a little play though).

simplechamp · 08.10.2009, 11:21 PM

Thanks for asking that question Nautilus, I'm about to do the V3 hybrid install myself and have never shimmed a diff before.

I bought some 6mm shims along with the 8mm so I can shift the diff left/right, and move the pinion in/out if needed.

simplechamp · 08.15.2009, 11:27 PM

I had been looking around for awhile to try and figure out what kind of diffs came with the V3 hybrids. Tonight I finally found that they are made by Caster Racing, and are the same diffs that are in Caster's new 1/8 electric buggies and truggies. The gears aren't spiral cut, but they do have a tiny bit of an arc to them, not sure what you'd call that. Are most normal diff gears cut with a slight arc in the teeth? Now I just have to find an alloy diff cup that will work with the Caster diffs and I'll be all set.

suicideneil · 08.16.2009, 11:07 AM

Straight cut gets are normally completely straight- caster seem to have done something in between with the slight arc (seen a few like that now), to reduce running noise yet maintain the same ratio.

simplechamp · 08.16.2009, 11:12 AM

Yeah it's really a very slight arc, I had to look at them real close to even see it.

I still don't get why so many buggies/truggies now use spiral cut, it seemed like the consensus in my "spiral vs. regular diff" thread was that spiral cut gears will cause your diff pinion to punch through the bearing. But most of the 1/8 racing vehicles are switching over. Do they use a roller bearing now or what? How do they deal with that extra push/pull force?